1. Field of the Invention
The present invention relates to a drawer type cursor controller for portable computers, more particularly to a drawer type cursor controller which is mounted in a housing below the keyboard of a portable computer.
2. The Prior Art
Following the increasing development of information industry, computers have had dramatic changes in their appearance. Electronic calculators in the earlier days consisted of vacuum tubes and usually occupied tremendous space. A simple computer might have to occupy at least one or two rooms. After the introduction of ICs, the volume of a computer was largely reduced. The recent development of VLSIs, further simplified both the structure and the volume of computers. For general computers, although the structure is simplified and the volume occupied is largely reduced, the monitor and system unit still occupied some space which makes the computers unsuitable for carrying. Portable computers were thereby developed. In the United States and Japan, such portable computers are much more welcome and popular than general computers. In Japan, such portable computers are referred to as Word Processor or WP, and become a necessary typing tool for general office-family, housewives, and students. However, since such portable computers have more functions than a typewriter, they are largely welcome in the USA market, too.
On the other hand, since the programming in the information industry tends to provide more and more simpler and easy-to-use products, application programs using a cursor controller has become the main stream in the computer field. Conventional cursor controller is a separate mouse or track ball which is inconvenient either in mounting or carrying. Connection wires across table top are both bothersome, too. The present invention meets the need for a cursor controller which can be integrally attached to a keyboard so that it will not occupy additional space while it is very convenient in operation.
As shown in FIG. 1, a common portable computer mainly consists of a top part 21, a monitor 22, a bottom part 11, a keyboard 12, and a cursor controller 4. The top part 21 is pivotly connected to the bottom part 11 with a pivot mechanism 3 so that the top part 21 may pivotly turn relative to the bottom part 11. Two entry control buttons 5 are provided beside the cursor controller 4 to control the on/off of the cursor controller 4.
FIG. 2 illustrates the operation of such conventional portable computer. Facing the monitor 22, a user enters and edits data with the keyboard 12. When the user wants to manipulate the cursor controller 4 located at upper portion of the keyboard 12, it is very inconvenient for him or her to reach across the keyboard 12 toward the cursor controller 4. The cursor controller 4 as referred to in this specification is a track ball with which the cursor on the screen may be freely moved in any and all directions.
Among the five fingers, the thumb gives the largest extent of movement and turns the track ball in more directions than any other four fingers. However, the cursor controller 4 provided with the conventional portable computers is generally located at upper left corner of the keyboard 12, hence it can not be conveniently manipulated by a left hand thumb without bending the left elbow at the same time. On the other hand, if the cursor controller 4 is to be manipulated with the right hand thumb, the user must diagonally reach out his or her right hand toward the upper left corner of the keyboard 12 which will inevitably hinder the movement of the user's left hand on the keyboard 12. If the other four fingers on the right hand are used to manipulate the cursor controller 4, limited extent of movement thereof and hindrance to the left hand will both exist.
In view of the above-mentioned disadvantages existing in the cursor controller for conventional portable computers, the present invention is developed to eliminate such drawbacks.